title: Association of intrastrain phase variation in quantity of capsular polysaccharide and teichoic acid with the virulence of Streptococcus pneumoniae.
abstract: The pneumococcus undergoes spontaneous phase variation between an opaque and a transparent colony form. In an animal model of systemic infection following intraperitoneal inoculation of mice, the opaque phenotype was significantly more virulent than the transparent for each of 3 strains examined. The opaque phenotype was associated with 1.2- to 5.6-fold greater amounts of capsular polysaccharide compared with the transparent using a sandwich ELISA. A similar technique comparing the amount of total teichoic acid showed that the transparent phenotype had 2.1- to 3.8-fold more immunodetectable teichoic acid. This difference was confirmed by comparing the incorporation of [3H]choline into teichoic acid. Cell fractionation revealed that variation in quantity of incorporated choline was due to differences in cell wall-associated teichoic acid. Results suggest that the pneumococcus phase varies between a virulent form with more capsular polysaccharide and less teichoic acid and an avirulent form with less capsular polysaccharide and more teichoic acid.
authors.affiliation: Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, 19104, USA.
authors.forename: J O
authors.initials: JO
authors.lastname: Kim
authors.forename: J N
authors.initials: JN
authors.lastname: Weiser
mesh_terms: D000818:Animals; D016667:Bacterial Capsules / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D015153:Blotting, Western; D002473:Cell Wall / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D010641:Phenotype; D011008:Pneumococcal Infections / Q000378:metabolism / Q000382:microbiology*; D011135:Polysaccharides, Bacterial / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D013682:Teichoic Acids / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D014170:Transformation, Genetic; D014774:Virulence / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D011135:Polysaccharides, Bacterial; D013682:Teichoic Acids; D002794:Choline